|Battle of Philippi|
|Part of Roman civil war|
location of Philippi
|Triumvirs, administering the Roman Republic||
Liberators, controlling the east|
Supported by Ptolemaic Egypt and the Parthian Empire
|Commanders and leaders|
|Octavian and Mark Antony||Brutus† and Cassius†|
|19 legions, allied cavalry 33,000; total over 100,000 men, up to 223,000 troops if auxiliary numbers matched legionary numbers||17 legions, allied cavalry 17,000; total about 100,000 men, up to 187,000 troops if auxiliary numbers matched legionary numbers|
|Casualties and losses|
|?||Surrender of entire army|
The Battle of Philippi was the final battle in the Wars of the Second Triumvirate between the forces of Mark Antony and Octavian (the Triumvirate) against the forces of Julius Caesar's assassins Brutus and Cassius in 42 BC, at Philippi in the Roman province of Macedonia. The Second Triumvirate declared this civil war to avenge Julius Caesar's murder.
The battle consisted of two engagements in the plain west of the ancient city of Philippi. The first occurred on the first week of October; Brutus faced Octavian, while Antony's forces were up against those of Cassius.
At first, Brutus pushed back Octavian and entered his army's camp. But to the south, Cassius was defeated by Antony, and committed suicide after hearing a false report that Brutus had also failed. Brutus rallied Cassius' remaining troops and both sides ordered their army to retreat to their camps with their spoils. The battle was essentially a draw, but for Cassius' suicide. This deprived the Liberatores of their best commander.
A second encounter, on 23 October, finished off Brutus's forces, and he committed suicide in turn, leaving the triumvirate in control of the Roman Republic. The Battle of Philippi marked the highest point of Antony's career: at that time he was the most famous Roman general and the senior partner of the Second Triumvirate. Antony's life was defined in this moment.